1. Field of the Invention
The present invention relates to an optical module and method of manufacture thereof, to a semiconductor device, and to an optical transmission device.
2. Description of Related Art
In recent years, there has been a trend toward increased speeds and volumes in data communications, and developments in optical communications continue. Generally, in optical communications, an electrical signal is converted to an optical signal, the optical signal is transmitted through an optical fiber, and then the received optical signal is converted to an electrical signal. The conversion between electrical signals and optical signals is done by optical elements.
For example, Japanese Patent Application Laid-Open No. 10-339824 discloses an optical fiber positioned and fixed on a platform in which a V-groove is formed, to constitute an optical module.
However, a conventional optical module has an optical fiber and optical element formed integrally, and it is further necessary to electrically connect this optical module to a semiconductor chip.
The present invention solves this problem, and has as its objective the provision of an optical module not requiring connection to a semiconductor chip and method of manufacture thereof, of a semiconductor device and of an optical transmission device.
(1) According to a first aspect of the present invention, there is provided an optical module of the present invention comprising:
an optical waveguide;
an optical element having an optical section; and
a semiconductor chip electrically connected to the optical element,
wherein the optical element and the semiconductor chip are packaged.
According to this aspect of the present invention, the optical element and semiconductor chip are packaged, and the semiconductor chip is incorporated into the optical module. Therefore, further connection of the optical module to a semiconductor chip is not required, and handling is made easier.
(2) In this optical module, a hole may be formed in the semiconductor chip; the optical waveguide may be inserted into the hole; and the optical element may be disposed so that the optical section and one end surface of the inserted optical waveguide are opposed.
By means of this, the optical waveguide is positioned by the hole formed in the semiconductor chip, and therefore the positioning accuracy of the optical section of the optical element and the end surface of the optical waveguide is increased.
(3) In this optical module, the hole may be a through hole.
(4) In this optical module, a light-transmitting sealant may be provided at the through hole.
By means of this, the optical waveguide is contacted with the sealant, and the positioning achieved.
(5) In this optical module, an underfill material may be provided between the optical element and the semiconductor chip.
By means of this, the optical element and semiconductor chip are protected, and also the connection therebetween can be made stable.
(6) In this optical module, an interconnect pattern may be formed on the semiconductor chip; a plurality of electrodes may be formed on the optical element; and at least one of the plurality of electrodes may be electrically connected to the interconnect pattern.
By means of this, since the optical element is mounted on the semiconductor chip, the optical module can be made more compact. To the semiconductor material constituting the semiconductor chip, the method of manufacture of the semiconductor device can be applied, and an interconnect pattern of high accuracy can be formed.
(7) This optical module may further comprise a substrate for supporting at least either of the semiconductor chip and the optical element.
(8) In this optical module, the substrate may assist the dispersion of heat from at least either of the semiconductor chip and the optical element.
(9) This optical module may further comprise external terminals provided on the substrate, and electrically connected to at least either of the optical element and the semiconductor chip.
(10) In this optical module, the semiconductor chip and the optical element may be sealed with resin.
By means of this, the semiconductor chip and optical element are protected by the resin.
(11) According to a second aspect of the present invention, there is provided a semiconductor device comprising: an optical element having an optical section; and a semiconductor chip electrically connected to the optical element, wherein the optical element and the semiconductor chip are packaged.
According to this aspect of the present invention, since the optical element and semiconductor chip are packaged, further connection of the optical module and semiconductor chip is not required, and handling is made easier.
(12) In this semiconductor device, the optical element and the semiconductor chip may be stacked.
(13) In this semiconductor device, a hole may be formed in the semiconductor chip; the optical element may be disposed so that one end surface of the semiconductor chip and the optical section are opposed; and the optical element and the semiconductor chip may be stacked.
(14) In this semiconductor device, the optical element and the semiconductor chip may be disposed on a substrate.
(15) In this semiconductor device, a hole may be formed in the substrate; the optical element may be disposed so that one end surface of the semiconductor chip and the optical section are opposed; and the optical element may be disposed on the substrate.
(16) According to a third aspect of the present invention, there is provided an optical transmission device comprising:
an optical waveguide;
a light-emitting element mounted with a light-emitting section facing one end surface of the optical waveguide;
a semiconductor chip electrically connected to the light-emitting element and packaged with the light-emitting element;
a light-receiving element mounted with a light-receiving section facing the other end surface of the optical waveguide; and
a semiconductor chip electrically connected to the light-receiving element and packaged with the light-receiving element.
According to this aspect of the present invention, the light-emitting element or light-receiving element and the semiconductor chip are packaged, and incorporate a semiconductor chip. Therefore, further connection between the light-emitting element or light-receiving element and the semiconductor chip is not required, and handling is made easier.
(17) This optical transmission device may further comprise: a plug connected to the light-emitting element; and a plug connected to the light-receiving element.
(18) According to a fourth aspect of the present invention, there is provided a method of manufacture of an optical module having at least an optical waveguide, an optical element having an optical section, and a semiconductor chip. This method comprises the steps of:
electrically connecting the optical element and the semiconductor chip;
relatively positioning the optical waveguide and the optical element; and
packaging the optical element and the semiconductor chip.
According to this aspect of the present invention, the optical element and semiconductor chip are packaged, and further connection of the optical module obtained to a semiconductor chip is not required, and handling is made easier.
(19) In this method of manufacture of an optical module, an interconnect pattern may be formed on the semiconductor chip; the optical element may have a plurality of electrodes; and the step of electrically connecting the optical element and the semiconductor chip may bond at least one of the plurality of electrodes to the interconnect pattern.
By means of this, merely by bonding the electrodes to the interconnect pattern, the electrical connection between the optical element and semiconductor chip can be achieved simply. Since the optical element is mounted on the semiconductor chip, the optical module can be made more compact. To the semiconductor material constituting the semiconductor chip, the method of manufacture of the semiconductor device can be applied, and an interconnect pattern of high accuracy can be formed.
(20) In this method of manufacture of an optical module, the electrode and the interconnect pattern may be bonded with a soldering material; and the positions of the optical element and semiconductor chip may be determined by the surface tension of the fused soldering material.
By means of this, by the surface tension of the soldering material the positioning of the optical element and semiconductor chip is carried out, and therefore a positioning step is not required.
(21) In this method of manufacture of an optical module, a hole may be formed in the semiconductor chip; and the step of relatively positioning the optical waveguide and the optical element may include a step of inserting the optical waveguide into the hole.
By means of this, by inserting the optical waveguide into the hole, the positioning of the optical waveguide and semiconductor chip is determined. Therefore, if the positioning of the optical element and semiconductor chip is carried out, the positioning of the optical element and optical waveguide can be carried out simply.
(22) In this method of manufacture of an optical module, the hole may be formed by a laser.
(23) In this method of manufacture of an optical module, the hole may be formed by etching.
(24) This method of manufacture of an optical module may further comprise a step of forming a depression in the region in which the hole is to be formed in the semiconductor chip by anisotropic etching, and then penetrating the depression by a laser, to form the hole in the semiconductor chip.
Anisotropic etching is widely carried out by the process of manufacture of a semiconductor device, and allows a depression of high accuracy to be formed. By means of anisotropic etching, the cross-section of the depression forms a V-shape, and therefore a hole formed by penetrating the depression with a laser has opening extremities which are tapered. Therefore, a hole with tapered opening extremities can be formed simply. The hole taper acts as a guide when the optical waveguide is inserted.
(25) This method of manufacture of an optical module may further comprise a step of providing an underfill material between the semiconductor chip and the optical element.
By means of this, by means of the underfill material, the optical element and semiconductor chip can be protected, and also the connection therebetween can be made stable.
(26) In this method of manufacture of an optical module, the step of packaging the optical element and the semiconductor chip may comprise sealing the optical element and the semiconductor chip with a resin.
By means of this, the semiconductor chip and optical element can be protected by the resin.
(27) This method of manufacture of an optical module may further comprise a step of providing a substrate to at least either of the semiconductor chip and the optical element.
(28) This method of manufacture of an optical module may further comprise a step in which external terminals electrically connected to at least either of the optical element and the semiconductor chip are provided on the substrate.